Configuration API for PubNub Go SDK

Go complete API reference for building real-time applications on PubNub, including basic usage and sample code. View on GoDoc

Configuration

pubnub.Config instance is storage for user-provided information which describe further PubNub client behavior. Configuration instance contains additional set of properties which allow performing precise PubNub client configuration.

Method(s)

To create configuration instance you can use the following function in the Go SDK:

config := pubnub.NewConfigWithUserId(UserId)

Parameter	Type	Required	Default	Description
SubscribeKey	string	Yes		SubscribeKey from Admin Portal.
PublishKey	string	Optional	None	PublishKey from Admin Portal (only required if publishing).
SecretKey	string	Optional	None	SecretKey (only required for modifying/revealing access permissions).
SetUserId	UserId	Yes		userId to use. The UserId object takes String as an argument. You should set a unique identifier for the user or the device that connects to PubNub. It's a UTF-8 encoded string of up to 92 alphanumeric characters. If you don't set the userId, you won't be able to connect to PubNub.
AuthKey	string	Optional	None	If Access Manager is utilized, client will use this AuthKey in all restricted requests.
Secure	bool	Optional	True	Use SSL.
MessageQueueOverflowCount	int	Optional	100	When the limit is exceeded by the number of messages received in a single subscribe request, a status event PNRequestMessageCountExceededCategory is fired.
ConnectTimeout	int	Optional	5	How long to wait before giving up connection to client. The value is in seconds.
SubscribeRequestTimeout	int	Optional	310	How long to keep the Subscribe loop running before disconnect.The value is in seconds.
NonSubscribeRequestTimeout	int	Optional	10	On Non subscribe operations, how long to wait for server response.The value is in seconds.
FilterExpression	string	Optional	None	Feature to subscribe with a custom filter expression.
Origin	string	Optional	ps.pndsn.com	Custom Origin if needed.
MaximumReconnectionRetries	int	Optional	unlimited (-1)	The config sets how many times to retry to reconnect before giving up.
SetPresenceTimeout	int	Optional	0	The setting with set the custom presence server timeout.The value is in seconds.
SetPresenceTimeoutWithCustomInterval	int	Optional	0	The setting with set the custom presence server timeout along with the custom interval to send the ping back to the server.The value is in seconds.
SuppressLeaveEvents	bool	Optional		When true the SDK doesn't send out the leave requests.
MaxIdleConnsPerHost	int	Optional	30	Used to set the value of HTTP Transport's MaxIdleConnsPerHost.
FileMessagePublishRetryLimit	int	Optional	5	The number of tries made in case of Publish File Message failure.
CryptoModule	crypto.NewAesCbcCryptor(CipherKey, UseRandomInitializationVector) crypto.NewLegacyCryptor(CipherKey, UseRandomInitializationVector)	Optional	None	The cryptography module used for encryption and decryption of messages and files. Takes the CipherKey and UseRandomInitializationVector parameters as arguments. For more information, refer to the CryptoModule section.
CipherKey	string	Optional	None	This way of setting this parameter is deprecated, pass it to CryptoModule instead. If CipherKey is passed, all communications to/from PubNub will be encrypted.
UseRandomInitializationVector	bool	Optional	true	This way of setting this parameter is deprecated, pass it to CryptoModule instead. When true the initialization vector (IV) is random for all requests (not just for file upload). When false the IV is hard-coded for all requests except for file upload.
UUID	string	Yes		This parameter is deprecated, use userId instead. UUID to use. You should set a unique UUID to identify the user or the device that connects to PubNub. If you don't set the UUID, you won't be able to connect to PubNub.

Disabling random initialization vector

Disable random initialization vector (IV) only for backward compatibility (<5.0.0) with existing applications. Never disable random IV on new applications.

CryptoModule

CryptoModule provides encrypt/decrypt functionality for messages and files. From the 7.1.2 release on, you can configure how the actual encryption/decryption algorithms work.

Each PubNub SDK is bundled with two ways of encryption: the legacy encryption with 128-bit cipher key entropy and the recommended 256 bit AES-CBC encryption. For more general information on how encryption works, refer to the Message Encryption and File Encryption sections.

If you do not explicitly set the CryptoModule in your app and have the cipherKey and useRandomInitializationVector params set in PubNub config, the client defaults to using the legacy encryption.

Legacy encryption with 128-bit cipher key entropy

You don't have to change your encryption configuration if you want to keep using the legacy encryption. If you want to use the recommended 256 bit AES-CBC encryption, you must explicitly set that in PubNub config.

CryptoModule configuration

To configure the CryptoModule to encrypt all messages/files, you can use the following methods in the Go SDK:

// encrypts using 256 bit AES-CBC cipher (recommended)
// decrypts data encrypted with the legacy and the 256 bit AES-CBC ciphers
config.CryptoModule = crypto.NewAesCbcCryptoModule("cipherKey", true)

// encrypts with 128-bit cipher key entropy (legacy)
// decrypts data encrypted with the legacy and the 256 bit AES-CBC ciphers
config.CryptoModule = crypto.NewLegacyModule("cipherKey", true)

Your client can decrypt content encrypted using either of the modules. This way, you can interact with historical messages or messages sent from older clients while encoding new messages using the more secure 256 bit AES-CBC cipher.

Older SDK versions

Apps built using the SDK versions lower than 7.1.2 will not be able to decrypt data encrypted using the 256 bit AES-CBC cipher. Make sure to update your clients or encrypt data using the legacy algorithm.

Basic Usage

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

config := pubnub.NewConfigWithUserId(UserId("myUniqueUserId") )

// SubscribeKey from Admin Portal
config.SubscribeKey = "SubscribeKey" // required

// PublishKey from Admin Portal (only required if publishing)
config.PublishKey = "PublishKey"

// SecretKey (only required for access operations, keep away from Android)
config.SecretKey = "SecretKey"

// the cryptography module used for encryption and decryption
config.CryptoModule = crypto.NewAesCbcCryptoModule("cipherKey", true)

// user ID to be used as a device identifier if you haven't set it already

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Rest Response from Server

Configured and ready to use client configuration instance.

Proxy Configuration

The following sample configures a client to use a proxy for subscribe requests:

var pn *pubnub.PubNub
config = pubnub.NewConfigWithUserId(UserId("myUniqueUserId")
config.UseHTTP2 = false

pn = pubnub.NewPubNub(config)

transport := &http.Transport{
    MaxIdleConnsPerHost: pn.Config.MaxIdleConnsPerHost,
    Dial: (&net.Dialer{
        Timeout:   time.Duration(pn.Config.ConnectTimeout) * time.Second,
        KeepAlive: 30 * time.Minute,
    }).Dial,
    ResponseHeaderTimeout: time.Duration(pn.Config.SubscribeRequestTimeout) * time.Second,
}
proxyURL, err := url.Parse(fmt.Sprintf("http://%s:%s@%s:%d", "proxyUser", "proxyPassword", "proxyServer", 8080))

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The following sample configures a client to use a proxy for non-subscribe requests:

var pn *pubnub.PubNub
config = pubnub.NewConfigWithUserId(UserId("myUniqueUserId")
config.UseHTTP2 = false

pn = pubnub.NewPubNub(config)

transport := &http.Transport{
    MaxIdleConnsPerHost: pn.Config.MaxIdleConnsPerHost,
    Dial: (&net.Dialer{
        Timeout:   time.Duration(pn.Config.ConnectTimeout) * time.Second,
        KeepAlive: 30 * time.Minute,
    }).Dial,
    ResponseHeaderTimeout: time.Duration(pn.Config.NonSubscribeRequestTimeout) * time.Second,
}
proxyURL, err := url.Parse(fmt.Sprintf("http://%s:%s@%s:%d", "proxyUser", "proxyPassword", "proxyServer", 8080))

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Initialization

Add PubNub to your project using one of the procedures defined in the Getting Started guide.

Description

This function is used for initializing the PubNub Client API context. This function must be called before attempting to utilize any API functionality in order to establish account level credentials such as PublishKey and SubscribeKey.

Method(s)

To Initialize PubNub you can use the following method(s) in the Go SDK:

pn := pubnub.NewPubNub(config)

Parameter	Type	Required	Description
config	Config	Yes	Goto Configuration for more details.

Basic Usage

Initialize the PubNub client API

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfigWithUserId("userId")
config.PublishKey = "my-pub-key"
config.SubscribeKey = "my-sub-key"
pn := pubnub.NewPubNub(config)

Returns

It returns the PubNub instance for invoking PubNub APIs like Publish(), Subscribe(), History(), HereNow(), etc.

Other Examples

Initialize a non-secure client

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfigWithUserId("userId")
config.PublishKey = "my-pub-key"
config.SubscribeKey = "my-sub-key"

pn := pubnub.NewPubNub(config)

Initialization for a Read-Only client

In the case where a client will only read messages and never publish to a channel, you can simply omit the PublishKey when initializing the client:

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfigWithUserId("userId")
config.SubscribeKey = "my-sub-key"

pn := pubnub.NewPubNub(config)

Event Listeners

You can be notified of connectivity status, message and presence notifications via the listeners.

Listeners should be added before calling the method.

Add Listeners

import (
    pubnub "github.com/pubnub/go"
)

listener := pubnub.NewListener()

go func() {
    for {
        select {
        case signal := <-listener.Signal:
            //Channel
            fmt.Println(signal.Channel)
            //Subscription
            fmt.Println(signal.Subscription)
            //Payload

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Remove Listeners

listener := pubnub.NewListener()

pn.AddListener(listener)

// some time later
pn.RemoveListener(listener)

Handling Disconnects

import (
    pubnub "github.com/pubnub/go"
)

 go func() {
    for {
        select {
        case status := <-listener.Status:
            switch status.Category {
            case pubnub.PNDisconnectedCategory:
                // handle disconnect here
            }
        case <-listener.Message:
        case <-listener.Presence:
        }

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Listener status events

Category	Description
PNTimeoutCategory	Processing has failed because of request time out.
PNDisconnectedCategory	The SDK is not able to reach PubNub servers because the machine or device are not connected to Internet or this has been lost, your ISP (Internet Service Provider) is having to troubles or perhaps or the SDK is behind of a proxy.
PNConnectedCategory	SDK subscribed with a new mix of channels (fired every time the channel / channel group mix changed).
PNAccessDeniedCategory	The SDK will announce this error when the Access Manager does not allow the subscription to a channel or a channel group.
PNBadRequestCategory	PubNub API server was unable to parse SDK request correctly.
PNCancelledCategory	Request was cancelled by user.
PNLoopStopCategory	Subscription loop has been stopped due some reasons.
PNReconnectedCategory	Subscription loop has been reconnected due some reasons.
PNAcknowledgmentCategory	PNAcknowledgmentCategory as the StatusCategory is the Acknowledgement of an operation (like Unsubscribe).
PNReconnectionAttemptsExhausted	The SDK loop has been stopped due maximum reconnection exhausted.
PNNoStubMatchedCategory/PNUnknownCategory	PNNoStubMatchedCategory as the StatusCategory means an unknown status category event occurred.
PNRequestMessageCountExceededCategory	PNRequestMessageCountExceededCategory is fired when the MessageQueueOverflowCount limit is exceeded by the number of messages received in a single subscribe request.

UserId

These functions are used to set/get a user ID on the fly.

Method(s)

To set/get UserId you can use the following method(s) in Go SDK:

config.SetUserId(UserId(string))

Parameter	Type	Required	Default	Description
UserId	string	Yes		UserId to be used as a device identifier. If you don't set the UserId, you won't be able to connect to PubNub.

config.GetUserId()

This method doesn't take any arguments.

Basic Usage

Set User ID

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfig()
config.SetUserId(UserId("myUniqueUserId"))

// set UserId in a single line
config := pubnub.NewConfigWithUserId("userId")

Get User ID

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfig()

fmt.Println(config.GetUserId)

Authentication Key

Setter and getter for users auth key.

Method(s)

config.AuthKey = string

Parameter	Type	Required	Description
AuthKey	string	Yes	If Access Manager is utilized, client will use this AuthKey in all restricted requests.

config.AuthKey

This method doesn't take any arguments.

Basic Usage

Set Auth Key

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfig()

config.AuthKey = "my_newauthkey"

Get Auth Key

fmt.Println(config.AuthKey)

Returns

None.

Filter Expression

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Stream filtering allows a subscriber to apply a filter to only receive messages that satisfy the conditions of the filter. The message filter is set by the subscribing client(s) but it is applied on the server side thus preventing unwanted messages (those that do not meet the conditions of the filter) from reaching the subscriber.

To set or get message filters, you can use the following methods. To learn more about filtering, refer to the Publish Messages documentation.

Method(s)

config.FilterExpression = string

Parameter	Type	Required	Description
filterExpression	string	Yes	PSV2 feature to Subscribe with a custom filter expression.

config.FilterExpression

This method doesn't take any arguments.

Basic Usage

Set Filter Expression

Required UserId

Always set the UserId to uniquely identify the user or device that connects to PubNub. This UserId should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UserId, you won't be able to connect to PubNub.

import (
    pubnub "github.com/pubnub/go"
)

config := pubnub.NewConfig()

config.FilterExpression = "such=wow"

Get Filter Expression

fmt.Println(config.FilterExpression)